High pressure contact for electrical connectors



July 23, 1968 o. A. VENN 3,394,341

HIGH PRESSURE CONTACT FOR ELECTRICAL CONNECTORS Filed Oct. 20, 1965 FIG.I g

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INVENT OR DOUGLAS V. VENN BY W 1? ATTORNEY United States Patent HIGHPRESSURE CONTACT FOR ELECTRICAL CONNECTORS Douglas A. Venn, Suitland,Md., assignor to the United States of America as represented by theSecretary of the Navy Filed Oct. 20, 1965, Ser. No. 499,112 6 Claims.(Cl. 339-252) ABSTRACT OF THE DISCLOSURE A high pressure contact forelectrical connectors wherein the male plug portion of the connector hasa prestressed longitudinal length greater than the longitudinal lengthof the hollowed portion of the female receptacle andwherein theprestressed radial dimension of the male plug means is less than thecross-section dimension of the inside surfaces of the sidewalls of thefemale receptacle so as to facilitate easy insertion of the plug meansinto the receptacle. Stressing means are located adjacent to the closedend of the receptacle and act to stress the plug portion of theconnector when the plug portion is forced into the receptacle by a veryhigh clamping or compressive force. As the plug is stressed it expandsradially within the receptacle so as to apply an extremely high matingpressure against the inner walls of the receptacle.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

The present invention relates generally to improvements in electricalconnectors and the like and more particularly to new and improvedelectrical connectors which are adapted to be used in connector arrays.Insertion of the male plug portion of the connector of this inventioninto the female receptacle portion is extremely easy, and an extremelyreliable, high-pressure, noise-free connection is attained after theport-ions of the connector are firmly mated together, such as by aconventional jack screw when the connectors are situated in a connectorarray.

In the field of electrical connectors it has been the general practiceto employ bow pins, banana plugs, micropins, or the like which dependupon the forces supplied by inherent built-in spring tension to makeelectrical and physical contact with the conductive mating element,normally a tube or sleeve device of controlled inner diameter. Althoughsuch devices have served the purpose, they have not proved entirelysatisfactory under all conditions of service for the reasons that if apin or plug has lost its inherent effective spring tension by any meanssuch as overheating, stressing beyond the elastic limit due to abuse, orif the pin or plug is slightly malformed in manufacturing, either noelectrical connection is made or a noisy and ineffective electricalconnect-ion is made.

Other difficulties have been encountered in prior art connectors whichdepend upon the forces supplied by the built-in spring tension -of theplug or pin to make electrical and physical contact with the conductivemating element or receptacle. Because the plug or pin of prior artconnectors is larger in diameter than the inside diameter of thereceptacle, insertion into the receptacle is difficult, particularlywhere the connectors are situated in an array, for the reason that theplug or pin immediately contacts the inner surface of the side walls ofthe receptacle and so restricts the relative movement between the plugand receptacle, thus requiring the application of a high initialinsertion force. This high initial insertion force often results in thebreaking or buckling of the plugs or pins, particularly where any smallmisalignment occurs between the plug and the receptacle.

The general purpose of this invention is to provide a reliable,high-pressure contact, noise-free, electrical connector which embracesall the advantages of similarly employed electrical connectors andpossesses none of the aforedescribed disadvantages. To attain this thepresent invention contemplates a unique electrical connector adapted tobe used in connector arrays which comprise a plurality of the connectorsof this invention whereby easy initial insertion of the plug or pin intothe receptacle is achieved and whereby a reliable, noise-free,electrical connection results, even though the plug or pin has beenstressed beyond the elastic limit, has lost its inherent tension, or hasbeen malformed due to manufacturing.

An object of the present invention is the provision of a new electricalconnector for providing a reliable, highpressure, noise-free electricalconnection.

Another object is to provide a new electrical connector which allows anoverstressed or malformed plug or pin to form a reliable, high-pressure,noise-free electrical connection.

A further object of the invention is the provision of a reliable,high-pressure, noise-free, electrical connector in which the plug or pinportion is easily insertable within the receptacle portion of theconnector.

Still another object is to provide a reliable highpressure, noise-freeelectrical connector which causes the plug or pin portion to be stressedin such a manner as to apply an extremely high mating pressure againstthe inner walls of the receptacle portion of the connector.

With these and other objects in view, as will hereinafter more fullyappear, and which will be more particularly pointed out in the appendedclaims, reference is now made to the following description taken inconnection with the accompanying drawings in which:

FIG. 1 shows a section of a properly mated prior art electricalconnector.

FIG. 2 illustrates a section of a prior art electrical connector wherethere is no electrical connection due to abuse, stressing beyond theelastic limit, or malformation of the plug or pin.

FIGS. 3A and 3B show sections of one embodiment of the invention.

FIGS. 4 and 5 illustrate sections of modified forms of the electricalconnector of FIGS. 3A and 3B.

Referring now to the drawings wherein like reference charactersdesignate like or corresponding parts throughout the several views,there is shown in FIG. 1 a conventional receptacle 11 containing a maleplug or pin 12 which is properly mated to the female receptacle 11 atcontact points 13 and 14.

FIG. 2 illustrates a conventional female receptacle 11 containing a plugor pin 12 which has been abused, stressed beyond its elastic limit ormalformed in the manufacturing process to such an extentthat there is noelectrical connection such as at 13 and 14 in FIG. 1.

FIG. 3A, illustrating one concept of the present invention, shows aconventional receptacle 11 partially containing conductive plug or pin12. Anvil block or stressing means 15 which is formed of rubber,plastic, metal or like compressible material, is located withinreceptacle 11 adjacent to the closed end of the receptacle.

FIG. 33 illustrates receptacle 11 completely containing plug or pin 12so that the shoulder 16 of the plug or pin is seated firmly against theshoulder 17 of the receptacle, and so that plug or pin 12 is forcedagainst the anvil block or stressing means 15 at contact area 18 andagainst the inner Walls of receptacle 11 at contact areas 19 and 20.

' In FIG.4 there is shown another embodimentwherein the stressing meanswithin receptacle 11 comprises anvil block 15 and a spring 21 locatedbetween the anvil block and the closed end of receptacle 11.

Referring now to FIG. there is illustrated a receptacle 22, with ahollow portion 24 which has a longitudinal length shorter than thepre-inserted length of plug 12 which, when it is forced to be completelycontained by the receptacle 22 so that the shoulder 16 firmlyseatsagainst shoulder 23 and its point is forced at contact point 25, theplug 12 radially xpands and is forced against the inner walls ofreceptacle 22 at contact areas 26 and 27, thereby making secureelectrical and mechanical engagement.

In the operation of one embodiment of the invention, as exemplified byFIG. 3A, the plug or pin 12 is easily inserted into the receptacle 11 upto the point at which the plug or pin strikes the anvil block 15,because the maximum diameter of the plug or pin is less than the insidediameter of the receptacle. This difference in diameters between theplug and receptacle eliminates the need of the very high insertion forcerequired in prior art connectors, and thus eliminates damage to the plugor pin caused by this high insertion force or by the misalignment of theplug and receptacle.

Then, as shown in FIG. 3B, by the application of a very high clamping orcompressive force, which may be generated by conventional means such asa jack screw (not shown), the plugs shoulder 16 is firmly seated againstthe receptacles shoulder 17 and the plug 12 is forced against the anvilblock so as to stress below the elastic limit and radially expand theplug in such a manner as to apply an extremely high mating pressureagainst the inner walls of the receptacle 11 at areas 19 and and againstthe anvil block 15 at contact area 18. This very high final matingpressure results in a reliable, low-resistance, electrical connectionunder extreme environmental conditions such as contaminated atmosphereheavy shock or vibration. The plugs are similarly forced, asaforedescribed, in the FIGS. 4 and 5 embodiments.

In order to facilitate fabrication of the connector and to permit largemanufacturing tolerance with respect to the length of the plugs or pinsand with respect to the length of the hollow portion of the receptacle,the anvil block 15 is preferably made of a compressible material, suchas rubber, plastic, or metal which will exert a controlled force againstthe plug or pin 12. For the same reason the anvil block 15 may be springloaded as shown in FIG. 4.

A similarly reliable, high-pressure, noise-free, electrical connectionresults without the use of an anvil block or spring by shortening theaxial length of the conventional receptacle 11, as illustrated in FIG. 5by receptacle 22.

The invention provides a reliable, electrical connector which iseffective under extreme environmental conditions. The connector has theadvantage of a very low initial insertion force when plug and receptaclealignment is critical and when plugs or pins are susceptible to damageby buckling or breaking as a result of plug and receptacle misalignment.The connector has a very high final mating pressure which is attainedeven though the plug or pin portion has been previously damaged byoverstressing or malformation and as a result a very reliable, lowresistance, electrical connection is achieved.

It should be understood, of course, that the foregoing .disclosurerelates to only preferred embodiments of the invention and that numerousmodifications or alterations may be made therein without departing fromthe spirit and scope of the invention as set forth in the appendedclaims.

What is claimed and desired to-be secured by Letters Patent of theUnited States is:

1. An electrical connector providing a reliable, highpr'essure,noise-free connection comprising:

female receptacle means having a longitudinal hollow portion ofpredetermined longitudinal length defined by side-walls;

radially stressable electrically conductive male plug means adapted tobe received withinsaid hollow portion of said receptacle means whereinsaid electrically conductive plug means has a prestressed longitudinallength greater than said predetermined longitudinal length and whereinthe prestressed radial dimension of said electrically conductive plugmeans is less than the cross-sectional dimension of the inside surfacesof said side-walls in order to facilitate easy insertion of saidelectrically conductive plug means into said receptacle means; and

stressing means located within said hollow portion of said receptaclemeans for stressing said electrically conductive plug means in such amanner as to apply an extremely high mating pressure between saidelectrically conductive male plug means and said sidewalls of saidreceptacle means.

2. An electrical connector as defined in claim 1 wherein said hollowportion has a closed end, and wherein said stressing means comprises:

a resilient anvil block which abuts said closed end of said hollowportion.

3. An electrical connector as defined in claim 2 wherein said resilientanvil block is comprised of rubber.

4. An electrical connector as defined in claim 2 Wherein said resilientanvil block is comprised of plastic material.

5. An electrical connector as defined in claim 2 Wherein said resilientanvil block is comprised of metal.

6. An electrical connector as defined in claim 1 wherein said hollowportion has a closed end, and wherein said stressing means comprises:

a spring which abuts said closed end of said hollow portion, and

an anvil block abutting the end of said spring opposite that end whichabuts said closed end. 7

References Cited UNITED STATES PATENTS 1,844,916 2/1932 Dykes 339--912,415,722 2/1947 Bauer 339-252 2,802,193 8/1957 Biba et a1 339258 X2,874,365 2/1959 WOofter 339258 X 2,958,020 10/1960 Eannarino 3393,171,183 3/1965 Johnston 339-255 X 3,252,127 5/1966 Woodward 339252 XFOREIGN PATENTS 323,560 1/1930 Great Britain.

MARVIN A. CHAMPION, Primary Examiner.

PERRY TEITELBAUM, Assistant Examiner.

